Tamper evident devices are in wide use to detect tampering with containers, especially in the food and pharmaceutical industries. A wide variety of tamper indicating devices are used. One such device may include typically seals, e.g., a membrane, over the container opening over which a cap is placed. Some tamper evident devices may be included on the cap either with or without the seals. Other tamper evident devices may include a film band attached over the cap. Still others include additional packaging over the container, e. g., blister packs, boxes and so on. Toothpaste tubes for example use boxes, satisfactory other tamper evident devices for such tubes not using additional packaging not presently being commercially available.
In structures which include a cap for a container two problems exist. One problem is detection of unauthorized opening of the cap and the second is, where the cap is attached to the container by snap action means, tampering with the unauthorized removal of the cap from the container, the latter not necessarily requiring opening of the cap. In the latter case for example, typical molded thermoplastic caps include a base member to which the cap is hinged. The base member may be snap fitted or threaded to the container. In one prior art arrangement the cap and base member include a tear band to provide evidence of opening the cap relative to the base member. The problem here is that the entire assembly may be removed without tamper evidence of such removal. This is not desirable.
In spout type devices such as toothpaste tubes, the tube is formed of extruded thermoplastic tubing. A spout is attached to one end of the tube and covered with a threaded cap. This arrangement is generally packaged in a box to provide tamper evidence. Because the tube and spout are produced with mass production techniques in which tamper evidence devices are not practical during formation of the spout, the use of boxes remains the current viable method of providing tamper evidence.
The present inventor recognizes a need to provide a cap structure which not only serves its usual function of covering the spout of an extruded thermoplastic tube or other container, but also provides tamper evidence of opening the cover or removal of the cover from the spout. None of the prior art structures deal with this problem. The problem is complicated by the fact that the tube must be processed with standard costly elaborate extrusion and spout forming processes which currently do not take into consideration the provision of providing tamper evidence.